Historically within various industries, for example the steel industry, various forms of packaging mediums and materials have been used for the wrapping of commercial or industrial products such as steel strip coils with commodity products such as stretch film in either a single substrate or multiple substrates dependent upon the level of protective packaging required.
In respect of automatic wrapping, machines and more specifically the carriage that drives the material carousel were designed to apply a stretch film grade that had vapour corrosion inhibitors (VCI) extruded within the film of 20 mu-50 mu with an overlap of 50-70% of the width of the film. Performance of this product type was very poor as protective levels were low with the robust handling and logistics encountered in the internal/external transport and storage of such steel coils.
When additional protection was required wrapping machines were built with a dual carriage system that applied two wrapping mediums to the product. The first layer generally consisted of a paper or plastic type material that afforded additional strength protection, which layer was then enclosed with a second layer of a stretch type film.
In the aluminium sector again automatic wrapping machines were designed to use a stretch film grade to protect aluminium profiles and sections. Generally the stretch film specification was between 25 mu-40 mu. Again issues were encountered with the film product not providing adequate protection to the aluminium profiles against damage due to handling, storage and transportation.
One of the key factors leading to damage to the product is a tendency, in storage, for the protective film to tear and split due to the tacky nature of the protective film, which when contacting another wrapped product would adhere to wrapping of that product.